"I know people get (upset) and go, 'They're going to take away the assault weapon.' Who ... needs an assault weapon? Like really, unless you're carrying out an assault. ... You can't hunt with it. ... Who's going to attack your house, a (expletive) army?"

The 66-year-old actor, writer and director said he also hopes for an additional focus on mental health to prevent future mass shootings.

"It's unbelievably horrible, what's happened. I think the biggest problem, seriously, is not so much guns. It's that every one of these people that have done these things in the past 30 years are friggin' crazy. Really crazy! And that's where we've dropped the ball: mental health," he said. "That to me is our biggest problem in the future, is insanity coupled with isolation."

Stallone is now in production on his next project, pairing up with the former "Raging Bull" Robert De Niro for "Grudge Match," about two aging boxers.

"People think it's going to be some geezer brawl. Really? OK, they're in for a surprise. I'm telling you. I've been working on the fight, the choreography. He's taking it deadly serious. Because no one wants to be shown up," Stallone said of De Niro. "It's going to be like a 'Rocky' fight. This will be 'Rocky 7,' with me fighting — with Rocky fighting the 'Raging Bull.'"